sql - Stored procedure has too many arguments specified C# -

i have sql server stored procedure like:

alter procedure p_updatecampaigngadget      @campaignid nvarchar(max),      @accountnumber nvarchar(max),      @phone01 nvarchar(max),      @callresult nvarchar(max),     @callstatuszone1 nvarchar(max),     @callstatuszone2 nvarchar(max),     @callbackdatetime01 nvarchar(max),      @firstname nvarchar(max),     @campaignenddatetime nvarchar(max) 

and code like:

 <asp:sqldatasource id="sqldatasource2" runat="server"        connectionstring="<%$ connectionstrings:ccap_ccconnectionstring %>"        selectcommand="p_showcampaigncontacts" selectcommandtype="storedprocedure"        updatecommand="p_updatecampaigngadget" updatecommandtype="storedprocedure">       <selectparameters>           <asp:querystringparameter defaultvalue="lab_outbound_c1_c" name="campaignid" querystringfield="id" type="string" />       </selectparameters>       <updateparameters>           <asp:parameter name="campaignid" type="string" />           <asp:parameter name="accountnumber" type="string" />           <asp:parameter name="phone01" type="string" />           <asp:parameter name="callresult" type="string" />           <asp:parameter name="callstatuszone1" type="string" />           <asp:parameter name="callstatuszone2" type="string" />           <asp:parameter name="callbackdatetime01" type="string" />           <asp:parameter name="firstname" type="string" />           <asp:parameter name="campaignenddatetime" type="string" />     </updateparameters> </asp:sqldatasource> 

i use procedure on gridview update.

why error

stored procedure has many arguments specified